jmurtap

Hello,
This group has been invaluable to my previous problems. But now I'm stumped and need help before I haul it to the dealer. We have a 2009 A4 quattro 2.0 that has a motor from a 2011 A4. It has been very problematic, but reliable to this point. Today the car wouldn't start it cranks two times and stops, towed it home and hooked up Ross tech, giving me a (CMP sensor (g40) / Engine speed sensor (G28)). I have already replace G40 a couple months ago. Now for the head scratching part, If I clear the fault it starts up and runs, and I can see both sensors sending feedback to the ECU that correlates to the rpm. However when I shut it down, back to the same thing it cranks twice and stops. Again if I clear the fault it fires up and runs normally until shut down and then it's a no go. I have isolated it to the engine control module and only clearing those two faults the car starts, also have pinged and monitored both of those sensors and they appear to be functioning while running, but refuses to allow the car to start. I have a engine speed or crankshaft sensor (G28) coming in tomorrow. But I have little faith that will fix the problem. Any help or advice or ideas are very much welcome. And thanks for your help in advance!!

-- Jason

SMac770

What's the actual codes? It's about the G40 and G28 sensors, but what's the actual logged DTC error number and text? comm issue, implausible signal, etc....

jmurtap

Good question, Its says.

P0016 00 [101] - Incorrect correlation
Not confirmed - Tested Since Memory Clear

SMac770

Yeah, not a problem I've had, but that sounds like chain concerns.
http://wiki.ross-tech.com/wiki/index...0/P0016/000022
https://forums.ross-tech.com/showthr...orrect-Correla

I'd be not driving the car at all, unless you know Audi will cover the bill to repair the engine when it blows up.
You need to check the camshaft chain tensioner and adaptation value.
https://www.audizine.com/forum/showt...ser-adaptation
https://www.audizine.com/forum/showt...Failure-Thread

Not sure why you have a 2011 motor already in a 2009, but the 2011 were no safer than 2009 from a reliability standpoint.
https://www.timingchainlitigation.com/
https://www.audizine.com/forum/showt...ction-Lawsuit/

Maybe it's not something that serious, but ....
Good luck.

jmurtap

So we took the car to the shop, and timing had jumped, chain tensioner failed, and intake cam and bearing housing had to be replaced. So final bill, new chain, chain tensioner, intake cam, and housing. With labor came to $2700. yikes